The invention relates to an escalator step, and more particularly, to an escalator step for attaching an edge strip easily and securely thereto.
From DE-A-35 30 263, there is known an escalator step in which an edge strip is attached to the front edge of the escalator step, which has appropriate recesses. To that end, the body of the escalator step has recess grooves into which corresponding projections on the edge strip are to be inserted. According to the preferred embodiments, the edge strip is held on the step body by way of a screwed fastening.
Although that escalator step allows impact protection to be provided at the comparatively sensitive front edge of the escalator step, it has the disadvantage that the susceptibility to breakdown increases in continuous operation. Obviously, the edge strip loosens as a result of the changing dynamic load as the passengers put weight on the step, or possibly as a result of contact with a comb plate of the escalator.
In many countries, edge strips of different colours are already prescribed. When using edge strips that are attached to the body of an escalator step, it is important that the edge strip be joined to the escalator step permanently and without play. Otherwise there is the risk that, in the course of time, dirt will find its way into resulting gaps and, although such dirt leads to a reduction in the play between the edge strip and the step body, it produces a tilting error which may result in a collision with the comb plate.
From DE-OS 196 51 585, there is known an escalator step in which there are attached to a step body edge strips of plastics material which cover at least one edge of the escalator step, especially the front. edge and/or both lateral edges, in such a manner that they are flush at the top with a tread of the escalator step. For fastening the edge strip to the step body, at least one undercut is provided on the step body, the edge strip being fastened to the step body via the undercut, in one piece, in an interlocking manner, by means of injection moulding.
That solution uses no screwed connections at all, so that there is no risk of the screwed connections being loosened as a result of mechanical vibrations and/or changing loads. In addition, the reliability of the mounting is improved considerably as compared with an edge strip fastened to the ends of pins simply by thermal anchoring. Separate mounting measures by means of screwed connections, which are comparatively labour-intensive, are also no longer required. However, a certain amount of additional expenditure is required during manufacture, since the entire escalator step must be mounted and the moulded bodies must be correspondingly large.
Further, there is known from U.S. Pat. No. 4,858,745 an escalator step in which there are provided on the escalator step lateral edge strips which in the unloaded condition leave an air gap between the escalator step and the fixed lateral boundary of the escalator, which air gap is able to close as a result of a load being placed on the peripheral opening. The edge strips can be inserted into appropriate recesses in the step body. The disadvantage of that design is, however, that the escalator step, which is manufactured as a die-cast part, must still be machined mechanically in order to provide adequate hold for the edge strips. That type of manufacture is, however, relatively expensive.
In order to fix the edge strips in their longitudinal direction, they are screwed to the step body in some embodiments.
The problem underlying the invention is, therefore, to produce an escalator step in which the edge strip can be both produced and secured without particular expense and the edge strips are nevertheless reliably mounted on the escalator step.
According to the invention, the snap connection is formed by means of clips provided on the edge strip or on the step body, which clips engage in corresponding recesses in the step body or in the edge strip, respectively. An especially simple method of mounting is thereby obtained and, in addition, the edge strips can be manufactured separately as an injection-moulded part, without the step body.
In order to secure the edge strip in position in the horizontal direction, it is preferred to provide projections on the edge strip or on the step body, which projections engage in corresponding recesses in the step body or in the edge strip, respectively. The projections are in the form, for example, of teeth, which extend parallel to the front edge of the escalator step.
Other advantages and embodiments of the invention are described in greater detail with reference to the following description of an exemplary embodiment, and the drawing.